Since we are playing the what if game.
What if Z confronted the kid and said, "Are you the little "insert racial slur here" breaking into houses?"(not the right thing to do, wrong to talk shit, but nothing illegal about that to my knowledge).
Kid then proceeds to beat Z's ass(illegal, assault) and depending on what kind of pussy Z is could be considered a threat to his life. Z, fearing for his life shoots the kid.(legal in the state of michigan at least to use deadly force).
To me that seems like criminally he would be not guilty, but probably opens up for a wrongful death civil lawsuit?
Now, what if Z confronted the kid and said, "Are you the little "insert racial slur here" breaking into houses?", and tried to physically restrain him(seems like we are talking some assault there). The kid defends himself, pulls away, etc... Then a scuffle breaks out. Z goes pussy mode and pops the kid.
To me that seems like that may end up being murder because he initiated the altercation.
Wit no witnesses, it seems to come down to the story of Z and a dead kid.
Either way, at this point, given the current facts, or rather lack thereof, I'd imagine a jury is going to have a hard time convicting him beyond a reasonable doubt. If that happens I'm pretty sure that town is going to burn...